Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756020Ab1FGQ3e (ORCPT ); Tue, 7 Jun 2011 12:29:34 -0400 Received: from e28smtp07.in.ibm.com ([122.248.162.7]:43173 "EHLO e28smtp07.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753522Ab1FGQ3c (ORCPT ); Tue, 7 Jun 2011 12:29:32 -0400 From: Trinabh Gupta Subject: [RFC PATCH V1 1/7] cpuidle: create bootparam "cpuidle.off=1" To: linux-pm@lists.linux-foundation.org, linuxppc-dev@ozlabs.org Cc: linux-kernel@vger.kernel.org Date: Tue, 07 Jun 2011 21:59:26 +0530 Message-ID: <20110607162922.6848.71783.stgit@tringupt.in.ibm.com> In-Reply-To: <20110607162847.6848.44707.stgit@tringupt.in.ibm.com> References: <20110607162847.6848.44707.stgit@tringupt.in.ibm.com> User-Agent: StGIT/0.14.3 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3515 Lines: 114 From: Len Brown useful for disabling cpuidle to fall back to architecture-default idle loop cpuidle drivers and governors will fail to register. on x86 they'll say so: intel_idle: intel_idle yielding to (null) ACPI: acpi_idle yielding to (null) Signed-off-by: Len Brown --- Documentation/kernel-parameters.txt | 3 +++ drivers/cpuidle/cpuidle.c | 10 ++++++++++ drivers/cpuidle/cpuidle.h | 1 + drivers/cpuidle/driver.c | 3 +++ drivers/cpuidle/governor.c | 3 +++ 5 files changed, 20 insertions(+), 0 deletions(-) diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index d9a203b..5697faf 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -546,6 +546,9 @@ bytes respectively. Such letter suffixes can also be entirely omitted. /proc//coredump_filter. See also Documentation/filesystems/proc.txt. + cpuidle.off=1 [CPU_IDLE] + disable the cpuidle sub-system + cpcihp_generic= [HW,PCI] Generic port I/O CompactPCI driver Format: ,,,[,] diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c index 406be83..a171b9e 100644 --- a/drivers/cpuidle/cpuidle.c +++ b/drivers/cpuidle/cpuidle.c @@ -28,6 +28,12 @@ LIST_HEAD(cpuidle_detected_devices); static void (*pm_idle_old)(void); static int enabled_devices; +static int off __read_mostly; + +int cpuidle_disabled(void) +{ + return off; +} #if defined(CONFIG_ARCH_HAS_CPU_IDLE_WAIT) static void cpuidle_kick_cpus(void) @@ -397,6 +403,9 @@ static int __init cpuidle_init(void) { int ret; + if (cpuidle_disabled()) + return -ENODEV; + pm_idle_old = pm_idle; ret = cpuidle_add_class_sysfs(&cpu_sysdev_class); @@ -408,4 +417,5 @@ static int __init cpuidle_init(void) return 0; } +module_param(off, int, 0444); core_initcall(cpuidle_init); diff --git a/drivers/cpuidle/cpuidle.h b/drivers/cpuidle/cpuidle.h index 33e50d5..38c3fd8 100644 --- a/drivers/cpuidle/cpuidle.h +++ b/drivers/cpuidle/cpuidle.h @@ -13,6 +13,7 @@ extern struct list_head cpuidle_governors; extern struct list_head cpuidle_detected_devices; extern struct mutex cpuidle_lock; extern spinlock_t cpuidle_driver_lock; +extern int cpuidle_disabled(void); /* idle loop */ extern void cpuidle_install_idle_handler(void); diff --git a/drivers/cpuidle/driver.c b/drivers/cpuidle/driver.c index 33e3189..284d7af 100644 --- a/drivers/cpuidle/driver.c +++ b/drivers/cpuidle/driver.c @@ -50,6 +50,9 @@ int cpuidle_register_driver(struct cpuidle_driver *drv) if (!drv) return -EINVAL; + if (cpuidle_disabled()) + return -ENODEV; + spin_lock(&cpuidle_driver_lock); if (cpuidle_curr_driver) { spin_unlock(&cpuidle_driver_lock); diff --git a/drivers/cpuidle/governor.c b/drivers/cpuidle/governor.c index 724c164..ea2f8e7 100644 --- a/drivers/cpuidle/governor.c +++ b/drivers/cpuidle/governor.c @@ -81,6 +81,9 @@ int cpuidle_register_governor(struct cpuidle_governor *gov) if (!gov || !gov->select) return -EINVAL; + if (cpuidle_disabled()) + return -ENODEV; + mutex_lock(&cpuidle_lock); if (__cpuidle_find_governor(gov->name) == NULL) { ret = 0; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/